Questions about placards, UN numbers, Identify, or anything else — we're here to help.
Placards · UN Numbers · Identify · Quiz
iOS · DahVio StudiosOn the Identify tab, hold the button and speak a UN number, placard description, or material name — e.g. "UN 1203" or "gasoline tanker rollover." Release to get a result. Exact UN numbers and known shipping names are matched instantly from the app's offline database; free-text descriptions are sent to generate an AI-assisted identification.
Not always. Exact UN numbers and known shipping names (typed, tapped, or spoken) resolve entirely offline. Only free-text or descriptive queries that aren't in the local list require a network connection to generate a result.
This means your query needed the network lookup and either the connection dropped or the request timed out. Check your connection and try again, or rephrase using the exact UN number or shipping name to get an instant offline result.
On the UN Numbers tab, tap the star icon on any entry to save it for quick access. Use the star filter next to the search bar to view only your starred entries. Starred items are saved on your device and persist between sessions.
Tap the graduation cap icon in the header to start a quiz. Choose a category — Placards, UN Numbers, Glossary, or Mixed — and answer a set of multiple-choice questions drawn from hand-written content covering the app's reference data.
Placard and UN number data has been cross-checked against the Emergency Response Guidebook (ERG) and 49 CFR §172.101. That said, HazMat Pro is a field reference and training aid — always confirm against the current official guidebook and your organization's procedures before acting on this data in an actual emergency.
Please email support@dahvio.com with the specific entry and what you believe is incorrect. Corrections are always welcome.
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Found a data error, have a feature request, or need help with something not covered above? Send a message and we'll get back to you promptly.
support@dahvio.com